Can't display symbol characters correctly when set use-default-font-for-symbols nil

[chansey97]

The following pos-tip-show call displays correctly when Emacs is started with -Q.

(require 'pos-tip)
(pos-tip-show "‘eldoc--message’") 

Screenshot

However, adding the symbol font and setting (setq use-default-font-for-symbols nil) will cause pos-tip-show displays incorrectly.

(set-face-attribute 'default nil :font (font-spec :family "Courier New" :size 14))
(setq use-default-font-for-symbols nil)
(set-fontset-font t 'symbol (font-spec :family "Segoe UI Symbol" :size 14) nil 'prepend)

(require 'pos-tip)
(pos-tip-show "‘eldoc--message’") ; 

Screenshot

It can only display two characters.

Removing the line (setq use-default-font-for-symbols nil) or set t (default) can workaround the problem but we have to (setq use-default-font-for-symbols nil) for some reason, see https://emacs.stackexchange.com/questions/81051/how-can-i-override-character-ranges-in-default-font

Environment: Emacs 29.3 on Windows 10 with pos-tip 0.4.7

Thanks.

Related issue: #23

[pitkali]

So, essentially, any fontset use breaks string width calculation. How fascinating. I'll take a look.

[pitkali]

Has it been a month already? Time flies.

Anyway, this seems to be Windows-specific. It does not reproduce on my Linux machine. I'll need to take a look on my other PC.